Villagers were evacuated from their homes as a wildfire swept across a mountainside in north Wales, prompting firefighters to declare a major incident.

People described hearing the crackling fire advancing down Conwy Mountain towards homes as ash fell from a sky turned dark by thick smoke.

A second major incident was declared in Derbyshire, where fire chiefs said they were working to protect homes, infrastructure and wildlife.

Wildfires have also burned in places including County Durham, Greater Manchester, East Sussex, West Sussex, Devon, Somerset and Greater London over the last few days.

Natural England said there remained an “exceptional fire risk” in pockets of southern Britain and a “very high” risk for much of England and Wales. A combination of continuing hot weather and high winds is making it hard to tackle the wildfires currently ablaze and increasing the risk of more starting.

North Wales fire and rescue service was called to Conwy Mountain in the early hours of Sunday and declared a major incident later that day. It said “hundreds of acres” of land were affected, and that at one point the front of the fire measured almost a mile across.

The fire service said the steep terrain made it hard to contain the blaze, which was whipped by strong winds.

A spokesperson asked people to avoid the area. “Local residents should keep windows and doors closed if affected by smoke. Everyone close to the Conwy Mountain who needed to evacuate has been contacted and supported through this process.”

One resident, Ben Campbell, fled with his wife, Michelle, and their three sons from Capelulo as the fire neared their home. He told the BBC: “The sound was worse than anything. It was so loud, the crackling. You could hear it coming down the mountain.” Another said she had felt helpless and scared as she was evacuated from her home.

Derbyshire fire and rescue service (DFRS) said there was a “large scale wildfire” at Tintwistle Moor caused by “tinder dry” ground. The operation to douse the flames included dropping water from helicopters.

Ellie Gillatt, a DFRS area manager, said: “Firefighters continue to face challenging conditions as they work to tackle the wildfire and protect the surrounding infrastructure and environment.

“This remains a significant and complex incident. DFRS has deployed multiple fire appliances and specialist wildfire resources.”

Extra firefighters from neighbouring services were called in to help, along with mountain rescue teams and the police.

Greater Manchester fire and rescue service was called to a moorland fire near Dovestone Reservoir.

A spokesperson said: “Due to strong winds, smoke from the fire travelled significant distances, with people reporting haze and the smell of smoke as far as Manchester city centre.”

In Walthamstow, east London, 125 firefighters tackled a blaze that affected a house, gardens and sheds and a railway embankment. Some residents were evacuated and two rest centres were set up. The cause of the fire is under investigation.

About 50 firefighters from London fire brigade also fought a wildfire in Orpington, in the south-east of the capital. The fire service said several acres of grass were alight across two fields.

Friederike Otto, a professor of climate science at Imperial College London, said last week that the climate crisis was making every heatwave hotter, with events such as this month’s heatwave more likely to occur.

“The heat we have seen this summer is only possible because of the 1.4C of climate change we have to date, due to the burning of fossil fuels,” she said.

Otto said it was misleading to use the term “new normal” when describing this year’s scorching summer heat. “The climate we have today is not stable and continues to warm as long as we continue to burn fossil fuels. As a result, what is ‘normal’ keeps shifting and we’re likely to see much hotter heatwaves like this one in the years to come.”